<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>p8_决定定位</title>
  <style>
    .fu {
      background-color:#ff0;
        position: relative;/*子绝父相*/
    }
    .fu>div {
      width: 100px;
      height: 100px;
    }
    .z1 {
        background-color: red;
    }
    .z2 {
        /*绝对定位:会脱离文档流,释放布局空间*/
        /*移动参照物:离自己最近的,有非静态定位属性的上层元素*/
        background-color: lime;
        position: absolute;
        bottom: 0;
        right: 0;
    }
    .z3 {
        background-color: blue;
    }
  </style>
</head>
<body>
<div class="fu">
  <div class="z1"></div>
  <div class="z2"></div>
  <div class="z3"></div>
</div>
</body>
</html>